1. Field of the Invention
The present invention relates to a mounting structure of a damper and the like in a speaker device.
2. Description of Related Art
Conventionally, there is known an external-magnet type speaker device including a vibration system having a damper, a diaphragm, a voice coil and a voice coil bobbin, and a magnetic circuit system having a yoke, an annular magnet and an annular plate.
Such a speaker device has a configuration in which inner peripheral edge portions of the damper and the diaphragm are mounted on an outer peripheral wall of the voice coil wound around the voice coil bobbin (or an outer peripheral wall of the voice coil bobbin) via an adhesive, respectively, for example. An example of the speaker device having the kind of form is disclosed in Japanese Patent Applications Laid-open under No. 2000-350290 and No. 10-210593.
In addition, as another example, there is known a configuration as follows: for the purpose of improving mounting strength of the damper to the voice coil (or the voice coil bobbin), based on the configuration of the above-mentioned speaker device, an annular resin member is further arranged on a lower side of the damper, and the inner peripheral edge portion of the damper, the inner peripheral edge portion of the resin member and the outer peripheral wall of the voice coil (or the voice coil bobbin) are bonded by the adhesive, respectively. An example of the speaker device having this kind of form is disclosed in Japanese Patent Application Laid-open under No. 2000-244999.
There is known a speaker device including a dump ring made of a soft material on a backward inner peripheral end of a spider for the purpose of absorbing an impact caused due to contact of the spider to the plate (for example, see Japanese Utility Model Publication No. 3-42798).
However, in the above-mentioned speaker device, at the time of large magnitude signal input, the damper is problematically cut at a border portion of the inner peripheral edge portion of the damper and the adhesive or problematically peels off the adhesive. This is caused mainly because a portion of the damper which is not fixed by the adhesive widely vibrates with respect to the border portion. In addition, in such a speaker device, since an adhesion area of the adhesive applied between the inner peripheral edge portions of the damper and the diaphragm and the outer peripheral wall of the voice coil (or the voice coil bobbin) is small, there is a problem that the adhesive between the damper and the voice coil (or the voice coil bobbin) peels at the time of the large magnitude signal input to the speaker device and the voice coil (or the voice coil bobbin) peels off the damper.